hi,
i can give a rough idea on maybe they did that... and it not hard...
1. of course always make a duplicate layer
2. then select the sofa and put on a seperate layer.. with this image there was some cloning to be done ...
2a. i did a duplicate of the softwa layer and reduce the opacitiy of that layer..... primarily soften the hard shadow..
3. make another duplicate of the orginal and desaturate it
4. then create a new layer and fill in with the color you want...
at this pint my layer pallet from bottom to top,,,
duplicate sofa with very low opacity
sofa
fill layer with the color you want... in this case looks like beige...
orginal layer that desaturated
duplicate of orginal layer
orginal layer
6. with the fill layer active, then using a soft edge erase at low opacity ...
then i erased the areas i wanted to show thru...!!
7. now the person put in a very soft shadow and what i did there was use the burn tool , soft edge and low opacity just put in the light shadow. arond the softa
that basically how i replicated how he did it... there probably other ways and techniques to do it... maybe use a couple of layer masks or what ever but anyway that give an idea one way to do it... hope that enough to get you started..